That seems like a simple question—it’s called Costco Wholesale Corporation, afterall. But that name is a little bit deceiving. First, to define the central terms: A retailer is a store that sells to consumers, while a wholesaler sells to other stores. With those definitions in mind, Costco is technically both, as it sells to both consumers and other businesses. However, since consumers are a larger portion of its clientele, it’s probably more accurate to call Costco a retailer. For what it’s worth, Costco describes itself as “a membership warehouse club†on its website, which is about 0 percent helpful.